Local levees face experts’ scrutiny

NIKKI BUSKEY Staff Writer

Tuesday

Apr 29, 2008 at 3:00 PMApr 29, 2008 at 6:03 PM

HOUMA -- State officials have chosen the eight scientists, experts and engineers who will be tasked with deciding whether plans for Terrebonne’s hurricane-protection system provide the best possible protection for local communities while minimizing its impact on area wetlands.

Terrebonne levee officials asked for the review in hopes of quelling criticism from environmentalists and scientists who question whether Morganza-to-the-Gulf’s proposed alignment would harm acres of eroding wetlands and argue that it would fail to provide adequate hurricane protection.

The technical-review panel, directed by the state Coastal Protection and Restoration Authority, is scheduled to begin meeting in June.

"I’m pleased that they’ve finally started to move with this committee. The idea has been on this table the long time," said Denise Reed, a professor with the department of Earth and Environmental Science at the University of New Orleans and a review panel member. "This is a good opportunity to do some thinking about how levees and wetlands interact and provide advice for any modifications that might need to be made."

Morganza-to-the-Gulf is a system of levees, floodgates and a lock on the Houma Navigation Canal designed to protect Terrebonne and part of Lafourche from storm-related flooding.

State officials insist that work on Morganza will not stop while the review is underway. The panel will evaluate the levee project and report back to state officials on Morganza even as portions of the levee project are designed and built.

"This review panel is not designed to slow the building of Morganza-to-the-Gulf," Garrett Graves, top aide to the governor on coastal issues, said in a written statement. "The panel will work to make sure the protection provided is the best possible. The state is committed to moving forward on this project."

The Governor’s Advisory Commission on Coastal Issues passed a resolution Sept. 13 in support of a scientific review of the project, but the final result was a long time coming, stalled by the gubernatorial election and the resulting state leadership changes.

The panel will review information about Morganza provided by the state, the Terrebonne Levee and Conservation District and the U.S. Army Corps of Engineers. Once that’s done, the panel will submit a written recommendation to CPRA.

"This is not about backroom conversations," Reed said. "We’re providing advice and background to the state."

Panelists say they aim to examine different aspects of the Morganza project.

Reed said she hopes to get more details about proposed environmental structures that would be built into the system, specifically concrete-box culverts that would allow water to flow through the levees throughout most of the year. The culverts are designed to be closed when a storm approaches to prevent saltwater intrusion. The setup has been called a "leaky levee," and would ideally maintain water flow in sensitive wetland areas.

"All we have really have on the ways it’s going to be operated is a really general description," Reed said. "I’m interested in addressing some of the concerns of the levee alignment and structures on the wetlands."

Jerome Zeringue, executive director of the Terrebonne Levee and Conservation District, said the U.S. Army Corps of Engineers is working on computer models that would determine how to maximize water flow through Morganza. The agency will also look at how many culverts would be needed in places like Lake Boudreaux and areas below the Falgout Canal to simulate what occurs naturally in the environment.

The modeling is scheduled to be complete by Thursday, with a final report released in August, Zeringue said. All that information will be provided to the panel.

"Our effort will depend on the quality of the material we’re given. We can only rely on the technical information and expertise that’s provided to on us," said Robert Twilley, director of the Wetland Biogeochemistry Institute at Louisiana State University in Baton Rouge and another review-panel member.

Twilley said he believes the most-important task the panel faces is examining whether Morganza’s current alignment and design reflects lessons learned during Hurricane Katrina.

The panel also faces a challenge in reconciling disagreements between local levee officials, who want Morganza built immediately, and the Army Corps of Engineers, which has initiated yet another project assessment to determine its feasibility and whether the benefits merit the cost, Twilley said.

"You have these two extremes, and fundamentally, in each of these camps, is still the question of whether the original design is efficient," Twilley said. "We don’t want any more unintended consequences."

The biggest question facing the panel, Twilley said, is one that lies at the heart of all major coastal projects ongoing in Louisiana: Are hurricane-protection projects compatible with restoration?

Morganza supporters say the levee project will help the eroding coast by maintaining the natural water flow while preventing saltwater from intruding and destroying more wetlands. At the same time, they say, it will provide hurricane protection.

"That’s the big discussion post-Katrina. Can we do both? Provide protection and restoration? A lot of people aren’t convinced we can," Twilley said.

Making Morganza compatible with Terrebonne’s fragile environment represents ecological engineering at its most complex, Twilley said.

"I look forward to the challenge," he added. "If we can get this right, it has huge implications for the rest of the state."

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